First powder the rava and Sabudana together then add powdered sugar and cardamom powder to it and mix well. Then slowly incorporate the ghee into the mixture and make balls. Make sure you do not add all the ghee all at once, little by little it must be added. Method is add little ghee make a ball then add some more then make another ball. So proceed like that if not balls will not form. Ghee must be warm so that ball holds shape.